# Tag Info

I m not sure, but I think this will help you. Here we use the tri-gram model, because the bi-gram model is not used for 3 words, and the answer is not the same as the bi-gram model for this corpus. $$P(a|a,b) = 0/1 = 0$$ $$P(b|b,a) = 0/1 =0$$ Similarly, all combinations of $\{a,b\}$ have a zero answer.